Electrical Losses - Underwriters-Labs/renewables.openwind.help GitHub Wiki
Electrical losses in Openwind are calculated using nominal phase voltages and wind turbine generator rated power (MW) within a 3-phase electrical system using the following electrical relationships and formulas:
Where:
I = Phase current (A)
PGEN = Wind Turbine Generator rated power (W)
VPHASE = Nominal phase voltage (V)
R = Total resistance of one phase conductor of a circuit (Ω)
RLEN = The resistance per unit length of a single-phase conductor (Ω/km), provide by the cable manufacturer.
L = Length of a three-phase circuit (km)
PLOSS = The calculated power loss (W)
In addition to line losses for the medium and high-voltage cables, Openwind calculates the losses due to the [substation transformer](Substation Layer) and the turbine transformers.
The electrical losses are calculated using the energy capture cases. For time series cases the collector system is simulated for each time-step and the appropriate electrical loss calculated. In the case of a probabilistic energy capture, each case (wind speed and direction) is simulated as a separate case taking account of the relative speed-ups across the site.
Figure 128: Electrical Properties of Turbine Type
Transformer losses are calculated as a linear function such that:
Ploss = NoLoadLoss + FullLoadLoss*(P/Prated)2
Where Prated is the rated power of the transformer, Ploss is the power lost by the transformer, P is the power going through the transformer, NoLoadLoss and FullLoadLoss are the losses at no and full load respectively.
Electrical losses are calculated after all other losses have been applied.